| Answer | Crossword Clue |
|---|---|
| APO | Letters on letters to soldiers |
| APO | Letters on letters to GIs |
| APO | Letters for soldiers' letters |
| ATTN | Letters on letters |
| USMAIL | Letters on letters |
| ENC | Letters on letters |
| ATTN | Letters on some letters |
| RSVP | Letters on some letters |
| ATTN | Letters on business letters |
| SWAK | Letters on love letters |
| SWAK | Letters on some letters |
| NYNY | Letters on Manhattan letters |
| RFD | Letters on some farm letters |
| SWAK | Letters on some love letters |
| SWAK | Letters on a love letter's envelope |
| USA | Letters on stamps on American letters |
| USMAIL | Letters on a box with letters |
